class Compiler
class BlockExtractor
class Block
def initialize(ip, block_id)
@ip = ip
@block_id = block_id
@instructions = []
@next = []
end
attr_reader :ip, :block_id, :instructions
def <<(insn)
@instructions << insn
end
def add_next(block, reason=:goto)
@next << [block, reason]
end
def next_blocks
@next
end
def size
@instructions.size
end
end
def initialize(iseq)
@iseq = iseq.opcodes
@block_id = 0
@blocks = Hash.new { |h,k| h[k] = Block.new(k, @block_id += 1) }
end
def run
run_from(0)
end
def run_from(start_ip)
if block = @blocks.key?(start_ip)
return @blocks[start_ip]
end
block = @blocks[start_ip]
ip = start_ip
total = @iseq.size
while ip < total
opcode = Rubinius::InstructionSet[@iseq[ip]]
size = opcode.size
if size == 1
block << opcode.opcode
else
ary = [opcode.opcode]
case size
when 2
ary << @iseq[ip + 1]
when 3
ary << @iseq[ip + 1]
ary << @iseq[ip + 2]
end
block << ary
end
case opcode.opcode
when :setup_unwind, :goto_if_false, :goto_if_true, :goto_if_defined
dest = @iseq[ip + 1]
block.add_next run_from(dest), :condition
block.add_next run_from(ip + 2)
return block
when :goto
dest = @iseq[ip + 1]
block.add_next run_from(dest)
return block
when :ret, :raise_exc
return block
end
ip += size
end
raise "control flowed off end"
end
class BlockInspector
def initialize(&block)
@seen_blocks = {}
@operation = block
end
def run(block)
return if @seen_blocks[block.block_id]
@seen_blocks[block.block_id] = true
@operation.call block
block.next_blocks.each do |sub, reason|
run sub
end
end
end
end
end
